Safety hood for grinding discs

ABSTRACT

A safety hood for grinding discs detachably mounted on a driver spindle including means detachably supporting said discs which means includes a projection which normally closes an opening in said hood through which said means and grinding wheel can be attached or detached from said driver spindle and which hood is supported by a bearing box for said spindle.

United States Patent Johansson SAFETY HOOD FOR GRINDING DISCS [75] Inventor: Bengt Johansson, Hisings Backa,

Sweden 73 Assignee: Centro-Maskin i Goteborg AB,,

Goteborg, Sweden [22] Filed: Feb. 14, 1973 [21] App]. No.: 332,421

[30] Foreign Application Priority Data Feb, 14, 1972 Sweden 1745/72 [52] US. Cl. 51/269 [51] Int. Cl B24b 55/04 [58] Field of Search 51/268, 269, 272, 168;

[56] References Cited UNITED STATES PATENTS 4/1966 Aller .l 51/168 Nov. 19, 1974 Hensley 51/269 Naslund 51/268 Primary Examiner-Al Lawrence Smith Assistant Examiner-Nicholas P. Godici 5 7] ABSTRACT A safety hood for grinding discs detachably mounted on a driver spindle including means detachably supporting said discs which means includes a projection which normally closes an opening in said hood through which said means and grinding wheel can be attached or detached from said. driver spindle and which hood is supported by a bearing box for said spindle.

1 Claim, 1 Drawing Figure SAFETY HOOD FOR GRINDING DISCS The present invention relates to a safety hood for grinding discs.

In addition to the requirement of the necessary strength, safety hoods for grinding discs must fulfill the requirement of a sufficiently enclosed design, so that in case of an eventual bursting of the disc, pieces of the same cannot be flung in such directions that serious injuries are caused. Thus, safety hoods for such discs, which are intended to grind with their periphery, are permitted to be open at the periphery only at the side, where the grinding discs contacts the work piece, and any opening in axially sidewise direction is not permitted. However, accessibility from the side is required in order to make it possible to release and remove the washer holding the grinding disc enabling the grinding disc to be pulled off from the spindle nose on which it is mounted. Safety hood of said type therefore have been equipped with a lateral shutter which can be opened. However, such a shutter means causes additional manufacturing cost and also a safety risk, if the shutter should not be carefully locked after being closed.

It is an object of the present invention to provide a device in connection with safety hoods for grinding discs, which fulfills the requirement of an enclosed design and possibility of change of grinding disc without the safety hood having to be removed but at which in spite of this a shutter is not necessary, by which ar-' rangement a cheaper and safer design is obtained.

An embodiment of the invention is illustrated in the accompanying drawing and described more in particular in the following. The FIGURE of the drawing illustrates the device in a cross section extending in an axial plane.

In the FIGURE a bearing box 1 with a rotatable shaft exhibiting a conical pivot 2 journalled therein is illustrated, said bearing box being mounted on a machine frame not shown. To the pivot 2 a sleeve is attached, exhibiting a first guide 3 and a second guide 4 passing on into a flange 5. A flange sleeve 6 with an inner guide 7 fits to the guide 3. The flange sleeve 6 exhibits further an outer guide 8 of the same diameter as the guide 4, a flange 9 of a design similar to the flange 5, and a tubular projection 10 opposed to the guide 8 and departing from the flange 9. The sleeve 3, 4, and the flange sleeve 6 can be tightly contracted by means of a annularly arranged set of screws 11. The sleeve 3, 4, 5 is kept in place on the pivot 2 by means of a shaft nut 12.

A safety hood 13 is attached to the bearing box 1 and comprises two end pieces 14 and 15 and a cylindrical jacket 16. The mantle piece 16 is bent in U-shape, its rounded upper portion having its centre in common with the centre of the shaft of the grinding disc, as is evident from the FlGURE. The end laterals 14, 15 at their outer edges fit to this shape, while at their centre they exhibit openings, at the end lateral 14 an opening 17, which is adapted to the bearing box 1 and at its edge fastened thereto by means of a weld. and at the end lateral 15 a U-shaped opening 18, the upper rounded portion of which having a diameter, which is somewhat greater than the diameter of the sleeve shaped projection of the flange sleeve 6, and the lower straight edges of which connect to said diameter and open out at the lower edge of the end lateral. The end lateral l5 leaves a space outside the pivot .2 corresponding the width of a grinding disc 19 and connects sidewise to the end portion of the projection 10. The parts 14, 15, 16 of the bursting safeguard are joined by means of weldmg.

During operation the grinding disc 19 is thread on the guides 4, 8 and is squeezed between the flanges 5 and 9 by tightening of the bolts 11. ll-lereby at the rotation of the sleeves together with the shaft 2 the grinding disc 19 by friction is also brought in rotation. In this position the grinding disc 19 is well enclosed by the bursting safeguard 13, which is open at the side only, in the drawing in downwards direction, where the work piece is positioned, which at this side serves the purpose of a kind of safeguard. The lateral opening 18 of the end lateral 15 of the bursting safeguard 13 is covered by the projection 10 of the flange sleeve 6 in such a way that no pieces loosened by a burst can be flung out.

When the grinding disc 19 is going to be removed the bolts 11 are removed, whereafter the flange sleeve 6 is pulled outwards until its guide 7 is liberated from the guide 3, so that the flange sleeve 6 can be brought downwards in the opening 18 and be removed. Hereafter the grinding disc 19 can be pulled off from the guide 4 and be brought past the end of the pivot 2 and the sleeve 3, 4, 5 to the position indicated by dot and dash lines. The grinding disc 19 can now be pulled downwards through the opening of the bursting safeguard 13. Insertion of a new grinding disc takes place in the reverse order.

As is evident from the above the bursting safeguard 13 has such a width that the grinding disc to be used can be introduced into the same outside of the spindle nose and up onto its provided guide. The fastening devices for the grinding disc, the flange sleeve 6 and the bolts 11 are accessible and removable from the outside, and in spite of the bursting safeguard being provided with a sufficiently great opening for this purpose, this opening does not involve any risk of pieces loosened by the burst being flung out through the same, because of in mounted position of the grinding disc it is covered by the projection 10 on the flange sleeve 6. The projection at the same time divides the portion of the lower opening of the bursting safeguard, which is outside the grinding disc and which must have at least the same width as this one in order to permit the mounting described, into two relatively small passages. Also this contributes to a lessening of the risk of bursted pieces being flung out.

The opening 18 does not necessarily have to extend until the edge of the wall 15, but it can be a round opening, straight through which the flange sleeve 6 is carried. The opening 18 then must have a diameter corresponding the diameter of the flange 9 and also the projection 10 shall be designed with this diameter.

There is another possibility to provide a round closed opening, viz. making the width of the bursting safeguard so great that both the flange 9 and the grinding discs can have room therein outside of the spindle nose. By this arrangement only the projection 10, which can have a smaller diameter than the one of the flange 9, needs to be brought out through the opening, thus not the flange itself.

What I claim is:

l. A grinding disc safety device comprising a grinding disc, which is intended for grinding with its peripherical part, a driven spindle nose, a flange piece being-detachpiece having a cylindrical projection, the outer diameter of which closely fits to the edges of said second opening, and the outer end of which closely fits to said side wall of said safety hood, said side wall being at a distance from the end of said spindle nose, which is at least as great as the width of said grinding disc, so that said grinding disc can be introduced into said safety hood through said first mentioned opening out side of said spindle nose in order to be mounted on the same. 

1. A grinding disc safety device comprising a grinding disc, which is intended for grinding with its peripherical part, a driven spindle nose, a flange piece being detachably mounted on said spindle nose, means detachably connecting said flange piece to said spindle nose, a safety hood enclosing a portion of said grinding disc, said safety hood having side walls with an opening therebetween with said disc projecting through said opening so that a segment of said disc is exposed, and said safety hood having a second opening in one side wall thereof, which is right in front of a side of said grinding disc, said second opening being arranged for rendering said flange piece and said connecting means accessible for mounting and demounting, said flange piece having a cylindrical projection, the outer diameter of which closely fits to the edges of said second opening, and the outer end of which closely fits to said side wall of said safety hood, said side wall being at a distance from the end of said spindle nose, which is at least as great as the width of said grinding disc, so that said grinding disc can be introduced into said safety hood through said first mentioned opening out side of said spindle nose in order to be mounted on the same. 